A new turbocharged 60◦ 2.7L V6 gasoline engine has been developed by Ford Motor Company for both the pickup truck and car applications. This engine was code named “Nano” due to its compact size and features a CGI cylinder block, an Aluminum ladder, an integrated exhaust manifold and twin turbochargers. The goal of this engine is to deliver 120HP/L, ULEV70 emission, fuel efficiency improvements and leadership level NVH. This paper describes the upfront design and optimization process used for the NVH development of this engine; it will discuss the critical NVH design features and the final results relative to the benchmarks.

Powerplant NVH decisions are sometimes made looking only at how the change impacts either the source radiated noise level or the source vibration. Depending on the Engine Configuration, those can be good approximations, but they can also be very misleading. By combining both noise sources into a Vehicle Equivalent noise level a much better analysis can be made of the impact of the design on the Customer perceived loudness. This paper will investigate several different senarios and identify how the airborne and the structureborne paths combine for I4, V6 and V8 engine configurations. Similar relationships will be shown for path as well as the source contributions.

Refrigerant flow-induced gurgling noise is perceived in automotive refrigerant systems which equipped with variable displacement compressors. In this study, the condition of the gurgling generation is investigated in vehicle level and the fundamental root cause is identified as the two-phase refrigerant flow entering the TXV. By conducting literature review, the acoustic characteristics of the flow patterns and the parameters affecting the flow regimes in horizontal and vertical tubes are summarized, and then the gurgling mechanism is explained as that the intermittent flow is developed at the evaporator inlet. In the end, the improved and feasible design for avoiding the intermittent flow (slug, plug or churn flow) or minimizing its formation is proposed and verified in refrigerant sub-system (RSS) level. Finally, the guidelines for the attenuation and suppression of the gurgle are provided.

In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle at 6.18 kHz is often perceived following air-conditioning (A/C) compressor engagements when driving at higher vehicle speed or during vehicle acceleration, especially when system equipped with the high-efficiency compressor or variable displacement compressor. The objectives of this paper are to conduct the noise source identification, investigate the key factors affecting the whistle excitation, and understand the mechanism of the whistle generation. The mechanism is hypothesized that the whistle is generated from the flow/acoustic excitation of the turbulent flow past the shallow cavity, reinforced by the acoustic/structural coupling between the tube structural and the transverse acoustic modes, and then transmitted to evaporator. To verify the mechanism, the transverse acoustic mode frequency is calculated and it is coincided to the one from measurement.

Quantifying Hands-free Call Quality in an Automobile Hands-free phone use is the most utilized use case for vehicles equipped with infotainment systems with external microphones that support connection to phones and implement speech recognition. Critically then, achieving hands-free phone call quality in a vehicle is problematic due to the extremely noisy nature of the vehicle environment. Noise generated by wind, mechanical and structural, tire to road, passengers, engine/exhaust, HVAC air pressure and flow are all significant contributors and sources of noise. Other factors influencing the quality of the phone call include microphone placement, cabin acoustics, seat position of the talker, noise reduction of the hands-free system, etc. This paper describes the work done to develop procedures and metrics to quantify the effects that influence the hands-free phone call quality.

The higher cylinder peak pressure and pressure rise rate of modern diesel and gasoline fueled engines tend to increase combustion noise while customers demand lower noise. The multiple degrees of freedom in engine control and calibration mean there is more scope to influence combustion noise but this must first be measured before it can be balanced with other attributes. An efficient means to realize this is to calculate combustion noise from the in-cylinder pressure measurements that are routinely acquired as part of the engine development process. This publication reviews the techniques required to ensure accurate and precise combustion noise measurements. First, the dynamic range must be maximized by using an analogue to digital converter with sufficient number of bits and selecting an appropriate range in the test equipment.

Light weighting of vehicle panels enclosing vehicle cabin causes NVH degradation since engine, road, and wind noise acoustic sources propagate to the vehicle interior through these panels. In order to reduce this NVH degradation, there is a need to develop new sound package materials and designs for use in lightweight vehicles. In this paper, we will focus on the use of SEA (Statistical Energy Analysis Tool) as a CAE design tool to develop sound packages for use in lightweight vehicle design to recover NVH deficiencies due to sheet metal light weighting actions. Statistical Energy Analysis results for vehicle level as well as dash and floor subsystem levels will be presented and SEA prediction capability for the sound package development for vehicle design will be discussed.

Gerotor oil pumps are widely used in automotive engine and transmission lubrication systems. The positive displacement characteristic of the pump design along with tight clearances between its different components result in formation of excessive pressure ripples within the pump and the attached oil galleries. Since the pressure ripples act as the excitation source to the engine components any alignment between pressure ripples excitation frequencies and engine components modal frequencies exacerbate the oil pump tonal noises radiated by the engine components. For this reason, it is necessary to perform engine radiated noise analysis with oil pump as the excitation source to assess the NVH performance of the pump. This paper describes a CAE method addressing engine radiated noise and whine due to the excitation from a gerotor oil pump. The method involves a multidisciplinary approach including CFD, frequency-response structural analysis and acoustic analysis.

Driveline plunge mechanism dynamics has a significant contribution to the driver’s perceivable transient NVH error states and to the transmission shift quality. As it accounts for the pitch or roll movements of the front powerplant and rear drive unit, the plunging joints exhibit resisting force in the fore-aft direction under various driveline torque levels. This paper tackles the difficult task of quantifying the coefficient of static friction and the coefficient of dynamic friction in a simple to use metric as it performs in the vehicle. The comparison of the dynamic friction to the static friction allows for the detection of the occurrence of stick-slip in the slip mechanism; which enables for immediate determination of the performance of the design parameters such as spline geometry, mating parts fit and finish, and lubrication. It also provides a simple format to compare a variety of designs available to the automotive design engineer.

This paper presents the methodology of predicting vehicle level automotive air-handling system air-rush noise sound quality (SQ) using the sub-system level measurement. Measurement setup in both vehicle level and sub-system levels are described. To assess the air-rush noise SQ, both 1/3 octave band sound pressure level (SPL) and overall Zwicker's loudness are used. The "Sound Quality Transfer Functions (SQTF)" between sub-system level and vehicle level are developed for the specified climate control modes and vehicle segment defined by J.D. Power & Associates, while the Zwicker's loudness is calculated using the un-weighted predicted 1/3 octave band SPLs by the Matlab-based program. The predicting models are demonstrated in a fairly good agreement with the measured data. The methodology is applied to the development of sub-system SQ requirement for upfront delivery of the optimum design to meet global customer satisfaction.

Various risk curves for head injury potential were assessed theoretically relative to field data. Specifically, two AIS2+ risk curves were studied: the HIC15-based risk curve from Mertz (1997) and the provisional, BRIC-based risk curve from Takhounts et al. (2013). These two risk curves were used to estimate attendant injury potential for belted drivers in full-engagement frontal crashes in the National Automotive Sampling System (NASS). The occupant responses pertaining to those crashes were estimated from representative math models, and the risk curves were used to convert event responses into event risks. The assessment was conducted from two perspectives: aggregate (0-56 kph) and a point-estimate (56 kph, barrier-like). Finally, the point-estimate assessment was supplemented by considering corresponding laboratory tests. The results from HIC15-based risk curve were understated, whereas the results from the BRIC-based risk curve were overstated.

A study of belted driver injury in various types of frontal impacts in the US field data was conducted. Specifically, subject to the Frontal Impact Taxonomy of Sullivan et al. (2008), injury potential of belted drivers in non-rollover, frontal impacts in the National Automotive Sampling System (NASS) was assessed. The field data pertained to 1985 - 2013 model-year light passenger vehicles in 1995 - 2012 calendar years of NASS. Two levels of injury were considered: AIS2+ and AIS3+. For ease of presentation, we grouped the injury data into lower- or upper-body regions. Frontal impacts were binned into eight taxonomic groups: Full-engagement, Offset, Narrow, Oblique, Side-swipe corner, High/low vert (i.e., over- and under-ride crashes), DZY-No rail (i.e., distributed crashes, but with negligible frame rail involvement), and Other. The results of the survey yielded insights into the distribution of belted-driver injury in NASS.

A deeper understanding of the complex phenomenology associated with the flow induced noise and vibration in a dynamic valve is of critical importance to the automotive industry. To this purpose, a two-dimensional axisymmetric numerical model has been developed to simulate the complex processes that are responsible for the noise and vibration in a poppet valve (or poppet). More specifically, an Eulerian multiphase flow model, a dynamic mesh and a user-defined function are utilized within the ANSYS-FLUENT software system in order to facilitate the modeling of the complicated two-phase fluid-structure interaction problem associated with the generation of noise and vibration in a poppet valve. In this strongly coupled simulation framework, the poppet valve which is driven by spring and various dynamical fluid forces (e.g., viscous and pressure forces), is modeled as an under-damped vibration system.

Abstract This paper proposes an approach to determine driver's driving behavior, style or habit during vehicle handling maneuvers and heavy traction and braking events in real-time. It utilizes intelligence inferred from driver's control inputs, vehicle dynamics states, measured signals, and variables processed inside existing control modules such as those of anti-lock braking, traction control, and electronic stability control systems. The algorithm developed for the proposed approach has been experimentally validated and shows the effectiveness in characterizing driver's handling behavior. Such driver behavior can be used for personalizing vehicle electronic controls, driver assistant and active safety systems, and the other vehicle control features.

Abstract A study and analysis of the relation of biodiesel chemical structures to the resulting soot characteristics and soot oxidative reactivity is presented. Soot samples generated from combustion of various methyl esters, alkanes, biodiesel and diesel fuels in laminar co-flow diffusion flames are analyzed to evaluate the impact of fuel-bound oxygen in fatty acid esters on soot oxidation behavior. Thermogravimetric analysis (TGA) of soot samples collected from diffusion flames show that chemical variations in biodiesel ester compounds have an impact on soot oxidative reactivity and soot characteristics in contrast to findings reported previously in the literature. Soot derived from methyl esters with shorter alkyl chains, such as methyl butyrate and methyl hexanoate, exhibit higher reactivity than those with longer carbon chain lengths, such as methyl oleate, which are more representative of biodiesel fuels.

Abstract Hydrogen fueled internal combustion engines have potential for high thermal efficiencies; however, high efficiency conditions can produce high nitrogen oxide emissions (NOx) that are challenging to treat using conventional 3-way catalysts. This work presents the results of an experimental study to reduce NOx emissions while retaining high thermal efficiencies in a single-cylinder research engine fueled with hydrogen. Specifically, the effects on engine performance of the injection of water into the intake air charge were explored. The hydrogen fuel was injected into the cylinder directly. Several parameters were varied during the study, including the amount of water injected into the intake charge, the amount of fuel injected, the phasing of the fuel injection, the number of fuel injection events, and the ignition timing. The results were compared with expectations for a conventionally operated hydrogen engine where load was controlled through changes in equivalence ratio.

Abstract The fatigue strength and failure behavior of A5754-O adhesively bonded single lap joints by a hot-curing epoxy adhesive were investigated in this paper. The single lap joints tested include balanced substrate joints (meaning same thickness) and unbalanced substrate joints, involving combinations of different substrate thicknesses. Cyclic fatigue test results show that the fatigue strength of bonded joints increase with the increasing substrate thickness. SEM and Energy Dispersive X-ray (EDX) were employed to investigate the failure mode of the joints. Two fatigue failure modes, substrate failure and failure within the adhesive were found in the testing. The failure mode of the joint changes from cohesive failure to substrate failure as the axial load is decreased, which reveals a fatigue resistance competition between the adhesive layer and the aluminum substrate.

Abstract Electric vehicles are receiving considerable attention because they offer a more efficient and sustainable transportation alternative compared to conventional fossil-fuel powered vehicles. Since the battery pack represents the primary energy storage component in an electric vehicle powertrain, it requires accurate monitoring and control. In order to effectively estimate the battery pack critical parameters such as the battery state of charge (SOC), state of health (SOH), and remaining capacity, a high-fidelity battery model is needed as part of a robust SOC estimation strategy. As the battery degrades, model parameters significantly change, and this model needs to account for all operating conditions throughout the battery's lifespan. For effective battery management system design, it is critical that the physical model adapts to parameter changes due to aging.

A computational aero-acoustics simulation on the aerodynamic noise generation of an automotive radiator fan assembly is carried out. Three-dimensional Computational Fluid Dynamics (CFD) simulation of the unsteady flow field was performed including the entire impeller and shroud to obtain the source of an audible broad-band flow noise between 2 to 4 kHz. Static pressure probes placed around the outer-periphery and at the center of the impeller inlet side and, at the shroud cavities to capture the noise sources. The static pressure at all probe locations were FFT (Fast Fourier Transform) processed and sound pressure level (SPL) was calculated. The sound pressure levels from the fan outer-periphery probes show the dominant source of blade passing frequency (BPF) and the broad-band noise. The BPF level is the strongest in fan outer-peripheral region because of large pressure fluctuations as a result of blade-passing.

Abstract This paper presents a numerical study of trace knocking combustion of ethanol/gasoline blends in a modern, single cylinder SI engine. Results are compared to experimental data from a prior, published work [1]. The engine is modeled using GT-Power and a two-zone combustion model containing detailed kinetic models. The two zone model uses a gasoline surrogate model [2] combined with a sub-model for nitric oxide (NO) [3] to simulate end-gas autoignition. Upstream, pre-vaporized fuel injection (UFI) and direct injection (DI) are modeled and compared to characterize ethanol's low autoignition reactivity and high charge cooling effects. Three ethanol/gasoline blends are studied: E0, E20, and E50. The modeled and experimental results demonstrate some systematic differences in the spark timing for trace knock across all three fuels, but the relative trends with engine load and ethanol content are consistent. Possible reasons causing the differences are discussed.

Abstract Exhaust pressures (P3) are hard parameters to measure and can be readily estimated, the cost of the sensors and the temperature in the exhaust system makes the implementation of an exhaust pressure sensor in a vehicle control system a costly endeavor. The contention with measured P3 is the accuracy required for proper engine and vehicle control can sometimes exceed the accuracy specification of market available sensors and existing models. A turbine inlet exhaust pressure observer model based on isentropic expansion and heat transfer across a turbocharger turbine was developed and investigated in this paper. The model uses 4 main components; an open loop P3 orifice flow model, a model of isentropic expansion across the turbine, a turbine and pipe heat transfer models and an integrator with the deviation in the downstream turbine outlet parameter.

While weight reduction in automotive design and manufacturing have been on-going for several years, in the area of powertrain technology, light-weighting has been a difficult challenge to overcome due to functional requirements, as well as material and manufacturing constraints. Ford Motor Company, as part of the Multi Material Lightweight Vehicle (MMLV) project with Vehma International and the US Department of Energy, worked with its material supplier, BASF, to design and develop a carbon fiber Front Cover and Oil Pan, based off the current Fox I3 Gasoline Turbocharged Direct Injection (GTDI) Engine. The effort produced a reduced weight Front Cover and Oil Pan, that were both structurally strong enough to support the engine attachment to the frame rail and as well as meeting all the powertrain bending stress targets that are seen in the current engine.

Abstract This paper proposes an approach that characterizes a driver's driving behavior and style in real-time during car-following drives. It uses an online learning of the evolving Takagi-Sugeno fuzzy model combined with the Markov model. The inputs fed into the proposed algorithm are from the measured signals of on-board sensors equipped with current vehicles, including the relative distance sensors for Adaptive Cruise Control feature and the accelerometer for Electronic Stability Control feature. The approach is verified using data collected using a test vehicle from several car-following test trips. The effectiveness of the proposed approach has been shown in the paper.

In the quest for reducing fuel consumption the demand for light weight engines is increasing. The design of several key components; cylinder block, connecting rod and cylinder head cam carrier are examined for mass reduction opportunities within the US DOE and Ford Motor Company funded MMLV project. Within this paper the mass reduction and durability performance of several key powertrain components are discussed. A new hybrid aluminum cylinder block with fractured split powder metal bulkhead inserts that tie the head bolts to the main bearing cap bolts was designed to meet the highly loaded characteristics of today’s modern turbocharged engines. This new hybrid aluminum cylinder block design resulted in a 40% or 9.46 kg mass reduction in comparison to the production 1.0L I3 grey cast iron cylinder block while meeting the same stringent durability requirements. Similarly, a new forged aluminum connecting rod was designed to replace the forged powder metal connecting rod.

Paper Title: MMLV - Lightweight Transmission Components Author: John Sabo, Magna International Abstract: The Multi-Material Lightweight Vehicle (“MMLV”) is a lightweight vehicle development project between Ford and Magna International, 50% co-funded by US Department of Energy (DOE) and Canadian Provincial grants. The goal of the project is to use lightweight material systems and manufacturing technologies to achieve significant overall weight reduction and demonstrate viability of such design by component-level testing. This paper presents a summary of the MMLV design development for lightweight transmission and driveline components, supported by extensive use of CAE analysis and component-level testing of prototype parts. A total mass reduction of 14kg (13.8%) relative to the 2012 Fusion baseline vehicle transmission and driveline components was achieved.

MMLV: Vehicle Durability Design, Simulation and Testing Nikhil Bolar1, Allen T. Li2, Jeff Wallace2 1Magna International 2Ford Motor Company Magna International, Ford Motor Company, and the U.S. Department of Energy initiated the Multi Materials Lightweight Vehicle (MMLV) Project in 2012. A mass reduction of 23.5% relative to a baseline 2013 Ford Fusion has been achieved. The three key attributes of structural performance evaluation for vehicle development are Safety, Noise, Vibration and Harshness (NVH) and Durability. This paper presents the full vehicle durability assessment of the MMLV Mach-I Concept Vehicle using CAE simulation of the body-in-white structure, subframe and closure designs, as well as the full vehicle field durability test at the Ford Motor Company Michigan Proving Ground.

Abstract The performance of an organic Rankine cycle (ORC) that recovers heat from the exhaust of a heavy-duty diesel engine was simulated. The work was an extension of a prior study that simulated the performance of an experimental ORC system developed and tested at Oak Ridge National laboratory (ORNL). The experimental data were used to set model parameters and validate the results of that simulation. For the current study the model was adapted to consider a 15 liter turbocharged engine versus the original 1.9 liter light-duty automotive turbodiesel studied by ORNL. Exhaust flow rate and temperature data for the heavy-duty engine were obtained from Southwest Research Institute (SwRI) for a range of steady-state engine speeds and loads without EGR. Because of the considerably higher exhaust gas flow rates of the heavy-duty engine, relative to the engine tested by ORNL, a different heat exchanger type was considered in order to keep exhaust pressure drop within practical bounds.

Abstract Designing a vehicle body involves meeting numerous performance requirements related to different attributes such as NVH, Durability, Safety, and others. Multi-Disciplinary Optimization (MDO) is an efficient way to develop a design that optimizes vehicle performance while minimizing the weight. Since a body design evolves in course of the product development cycle, it is essential to repeat the MDO process several times as a design matures and more accurate data become available. This paper presents a real life application of the MDO process to reduce weight while optimizing performance over the design cycle of the 2015 Mustang. The paper discusses the timing and results of the applied Multi-Disciplinary Optimization process. The attributes considered during optimization include Safety, Durability and Body NVH.

Abstract As the world's largest auto producer and consumer, China is both the most promising and complex market given the country's rapid economic growth, huge population, and many regional and segment preference differences. This research is aimed at developing data-driven demand models for customer preference analysis and prediction under a competitive market environment. Regional analysis is first used to understand the impact of geographical factors on customer preference. After a comprehensive data exploration, a customer-level mixed logit model is built to shed light on fast-growing vehicle segments in the Chinese auto market. By combining the data of vehicle purchase, consideration, and past choice, cross-shopping behaviors and brand influence are explicitly modeled in addition to the impact of customer demographics, usage behaviors, and attributes of vehicles.

Abstract Magnesium die-cast alloys are known to have a layered microstructure composed of: (1) An outer skin layer characterized by a refined microstructure that is relatively defect-free; and (2) A “core” (interior) layer with a coarser microstructure having a higher concentration of features such as porosity and externally solidified grains (ESGs). Because of the difference in microstructural features, it has been long suggested that removal of the surface layer by machining could result in reduced mechanical properties in tested tensile samples. To examine the influence of the skin layer on the mechanical properties, a series of round tensile bars of varying diameters were die-cast in a specially-designed mold using the AM60 Mg alloy. A select number of the samples were machined to different final diameters. Subsequently, all of the samples (as-cast as well as machined) were tested in tension.